Team Ucalegon's ants

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peterwaller
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Re: My first ant was not a success: Onto the second!

Post by peterwaller »

Usually the brown outs are due to the servo taking too much current when loaded and the BEC can't keep up.
Are you running the servo from the 5v rail if so try connecting the servo power wire direct to the full battery voltage (it is rated at 7.2v) and see if that helps it will give you more servo power as well.
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Shakey
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Re: My first ant was not a success: Onto the second!

Post by Shakey »

tomchaps wrote:Help! Finalized the chassis, got everything in, but when practicing driving I realized that I have an electronics problem.

When I actually try to lift anything, the receiver browns out. With no weight on it, it flaps up and down happily, but if there is any torque on the servo, it just dies.

I'm using tinyESCs from fingertech, which should be able to handle this.

Argh! What can I do? Safety checkin is in about eleven hours!
Is the Pink servo's red wire going to the LiPo? These servos are used as they get their power right off the LiPo giving them that little bit more power. At the moment it sounds like you may be drawing from the BEC and causing the 5v rail to dip when using the weapon.

If not try and find a 200-500 uF capacitor and jam it on the 5v rail.

EDIT: ninja'd by pete
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tomchaps
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Re: My first ant was not a success: Onto the second!

Post by tomchaps »

Okay, so to be clear: I remove the red wire from the receiver, and instead wire it directly into a splice on the red wire from the LiPo? Leave the other two heading into the receiver as before?

Do you just solder it directly in? I'm guessing I'll want to use this servo in other, better bits later on--so I'm a bit nervous about messing with it...

Thanks for all your help!
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Shakey
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Re: My first ant was not a success: Onto the second!

Post by Shakey »

tomchaps wrote:Okay, so to be clear: I remove the red wire from the receiver, and instead wire it directly into a splice on the red wire from the LiPo? Leave the other two heading into the receiver as before?

Do you just solder it directly in? I'm guessing I'll want to use this servo in other, better bits later on--so I'm a bit nervous about messing with it...

Thanks for all your help!
Yeah just cut the red wire from the receiver and connect it to somewhere that's the full battery voltage. Leaving the black and yellow going into the receiver. I normally just solder it on, it's easy enough to desolder the single wire later.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!
tomchaps
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Re: My first ant was not a success: Onto the second!

Post by tomchaps »

Need to leave in about 45 minutes, plugging the soldering iron in now!

Cutting it a tiny bit close...

Thanks again.
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peterwaller
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Re: My first ant was not a success: Onto the second!

Post by peterwaller »

Yes you connect it to a point after the on / off switch if you have one so when you switch off the servo is also powered down.
The 0 v and signal wires still go to the receiver as before.
If you don't want to cut the servo lead it is possible to to remove the red wire and socket pin from the servo socket shell and use a header pin to connect it to the battery voltage as below, though you would need to insulate it.
Image
Alex beat me this time I had trouble uploading the picture.
Last edited by peterwaller on Sat Sep 16, 2017 2:56 pm, edited 2 times in total.
tomchaps
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Re: My first ant was not a success: Onto the second!

Post by tomchaps »

Made it with maybe ten minutes to spare, and the fix worked great--I had a ton of power in the flipper, no brownout issues at all. Again, thank you!

Of course, the first match I forgot to bend over one side of the paper clip that was the linkage to the servo, so I couldn't self-right after the first hit. (My flipper now has enough power that basically all it does is flip over and self-right, so that was frustrating.)

Second match, the servo arm came off, since I forgot to put that little screw into the center. Again, oops.

Still, it was a blast--I got to be in the pits with all the serious teams, and gossip with the local insect-bot folks, watch 220 pounders smash around. And I learned a lot--mostly about double-checking stuff.

I'll upload videos when I have them...
tomchaps
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Re: My first ant was not a success: Onto the second!

Post by tomchaps »

Finally found a video of Swarf at Robogames--the 3-person rumble at the end. I finally made a polycarb linkage rather than a paper clip, and it was the first time the servo arm didn't detach. It also meant the titanium didn't go all the way flush, so I grabbed a bit of plastic and duct tape, and extended the flipper a bit. It worked so much better! (I know you all told me to tape a bit of plastic to the front, but I didn't listen...) The scrap of plastic had the word "HAMMER" written on it, which turned by flipper into a hammerbot, I guess?

The rumble was against two vertical spinners, including the terrifying Rip Up (https://www.youtube.com/watch?v=g9XjRXr ... e=youtu.be)

The minirumble: https://www.youtube.com/watch?v=PrAz98QV3uw&t=13s
tomchaps
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Re: My first ant was not a success: Onto the second!

Post by tomchaps »

Does anyone know what screw to use on "the pink servo" (linked above at Hobbyking) for attaching the horn? I seem to have lost mine, and can't find the specs online.
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Re: Team Ucalegon's ants

Post by tomchaps »

Okay, so I now have three 150g ants, and our backyard arena is finished enough to use. Hopefully we can get a local league going soon!

Here's a video my son made of our recent "event", which was mostly an excuse to force us to finish building. My friend's bot broke very quickly, so it was mostly my cobbled-together pushybot versus my other two.

https://www.youtube.com/watch?v=GX4VUTI ... e=youtu.be

My spinner Jellytussle was pretty bad--it didn't get great "bite", and its front wedges weren't low enough. Perhaps it would be better with just two wide "spikes" on the sides, rather than the flat wedgelets?

The flipper Swarf is probably what I'll run at Robogames. There are a ton of spinners in the mix, and it's more fun to run something different. With no pushouts (I think), it's hard to keep fighting high-KE bots, though.

The wedge Thingumy did surprisingly well for something I built entirely the night before, to be able to have a "target" bot that used my second transmitter. The triangle shape meant that it got flipped REALLY easily, and it can't drive upside-down. I should be able to adjust the shape to make it much better, though.
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Swarf small.jpg
Swarf small.jpg (150.08 KiB) Viewed 10977 times
Jellytussle small.jpg
Jellytussle small.jpg (215.32 KiB) Viewed 10977 times
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